Engine system is getting smaller in time and getting more powerful engine is main purpose of many OEMs. While engines are getting more powerful, by the time, it is also getting smaller and less stiff. Smaller engines with high power means, engine vibrates more and so generates more noise.Thus engine structure and also engine main components should be design to prevent this vibration. There are two main sources. One of them is combustion and other is inertia loads. Due to this sources engine structure can cause severe vibration and accordingly this can cause noise via transmitting it into vehicle with both structure and airborne. This paper focused on to reduce engine vibration level with changing the combustion inputs such as cylinder pressure parameters and also changing piston mass, conrod lenght and balancing parameters. Optimisation tool is used to obtain most robust design in terms of nvh.The combination of both engine structure and combustion is chosen to reduce vibration. Accordingly the parameters are used at engine CAE model and compared with each other with performing mount vibration analysis.This powertrain analysis results is used to perform vehicle level interiour noise assesment.Mount vibration analysis results are transmitted to vehicle interiour with using transfer function and that allow to decide and define best parameters in terms of customer,driver perspective. This study is purposed to obtain optimum combustion and inertia parameters in terms of both powertain level and vehicle level nvh analysis and to decide the best option it investigate and compared the results each other to obtain robust design.